Drying apparatus.



No. 685,287. Patented Oct. 29, |90I.

. A. P. MENDE.

DRYING APPARATUS.

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UNITED STATES' PATENT OFFICE.

ALEXANDER P. MENDE, OF NEW YORK, N. Y.

DRYING APPARATUS.

SPEIFICATION forming part of Letters Patent N o. 685,287, dated October29, 1901.

I Application filed October l5, 1900. Serial No. 33,079. (No model.)

To all whom t may concern.:

Be it known that I, ALEXANDER P. MENDE, a citizen of the United States,and a resident of New York city, county and State-of New York, haveinvented certain new and useful Improvements in Drying Apparatus, ofwhich the following is a specification.

This invention relates to a drying apparatus of the class known asvacuum-driers and in which the drying operation is greatly acceleratedby creating a vacuum within the drying-chamber.

The invention consists principally in so constructing the apparatus thata 'uniform vacuum and a constant temperature will be automaticallymaintained while the drying operation goes on, so that for the'samesetting of the apparatus an evenly-dried product will result.

The invention also consists in the various features of constructionfully pointed out in the claim.

In the accompanying drawings, Figure l is an end elevation, partly insection, of my improved drying apparatus; Fig. 2, a verticalcross-section on line 2 2, Fig. 5; Fig. 3, adetail section of thevacuum-regulating valve; Fig. 4:, a similar section through thesteaminlet valve; vand Fig. 5 a longitudinal section on line 5 Fig. 1'.

The letter a represents 'the shell of the drier, made of cylindrical orother form and open, preferably at both ends. These ends are adapted tobe closed by heads or doors a', hinged at a2 and tightened up by theswinging bolts a?. Within the shell a, is contained a track b, placed inalinement with tracks c, arranged outside of the shell and which may beswung up, Fig. 5, to clear the doors a' when the latter are to beopened. The track b supports a truck b', that in turn supports thedrying shelves. These shelves consist of coils d, arranged in horizontaltiers and connected by couplings d' to form a continuous pipe. Each tieris supported by transverse rods b2, connected to a frame b3, that ismounted upon the truck b. The steam or other heating medium is admittedto the uppermost coil d by inlet-pipe e and leaves the lowermost coil byoutlet-pipe f, the pipes e f being adapted to be removably coupled tothe coils d by the couplings e f'. These couplin gs are opened whenthe'truck is to be withdrawn for removing and replacing the materialunder treatment and are closed when the truck hasbeen rolled back intothe shell.

The shelves d should be open, so that the drying-spaces between theshelves communicate with one another.

While the material is subjected to the action of the heat the air withinthe shell a is simultaneously exhausted to accelerate the dryingoperation on principles well understood in vacuum-driers. This air andthe vapors or gases generated are carried od by a pipe g, connected toan air-pump g', the latterl receiving its steam-supply'by pipe g2.Within the pipe 'g is arranged a sprinkler g3 for vprecipitating thevapors.

With dierent materials under treatment it is of importance that thedegree of air rarefaction within the shell a should be dierent. It isalso of importance that any partial vacuum to which the drier has beenset should be automatically maintained, so that the material undertreatment and subsequent charges of similar material will be subjectedto a uniform action.

The means for automatically maintaining any vacuum desired and forpermitting a ready adjustment of such vacuum consists of a vacuum-valve.(More fully illustrated in Figi. 3.) The valve-casing h is mounted uponthe top of the shell a and is provided above the valve-seat h2 with asuction-chamber h5. This suctionechamber is provided with a nipple h",that receives one end of an elbow-pipe h3, the other end of which entersthe shell a. The pipe ha serves the double purpose of securing thevalve-casing to the exterior of the shell and also for establishingcommunication between the interior of the shell and the suction-chamberh5. The valve-stem h4 is connected to a beam i, turning at 'i' on frame2 and provided with a sliding counterbalancingweight 'i4 on one of itsarms and with a xed weight i5 on its other arm. In use the vacuum withinthe shell a is ascertained by a gage j, and the Weight 4 is adjustedalong its beam until the proper vacuum is indicated. This vacuum willnow be automatically maintained, because when the pump g' exhausts anexcessive amount of air the valve 72. will lift against the weightf4 toadmit suicientv loo air to reestablish the proper vacuum. NVhen theweight 4 is so set as to counterbalance weight 5,practically no vacuumwill be formed within the shell. It will thus be seen that any vacuum towhich the apparatus is set is automatically maintained. It is also ofimportance that the temperature to which the material is subjected, andwhich is ascertained by thermometer m, is automatically maintained at auniform degree. This is accomplished by a thermostat of the usual orsnitable construction and which it is not deemed necessary to describein detail.

The tube k of the thermostat containing the water or other eXpansiblemedium is so arranged within the shell a as to clear the truck andshelves. This medium acts by pipe k upon the diaphragm Z, Fig. 4, thatautomatically regulates the position of the valve l', through which thesteam is admitted from pipe e into the coil d. The pressure within thethermostat, and the consequent degree of heat within the drier, isregulated, as usual,

by the hand-wheel k2.

The operation of my improved drier will be readily understood. Thevacuum-valve and thermostat are set to produce the partial vacuum andtemperature desired for the particular' goods under treatment. The truckb is then withdrawn, the goods placed directly or in trays upon thecoils d, the truck is reintroduced, and the doors are closed. As thedrying-spaces between the shelves communicate with each other, theairand vapors will be evenly and simultaneously withd rawn will also beuniform. Thus it will be seen that the material is subjected to auniform treatment and that without constant watching an evenly-driedproduct will be obtained. This uniform treatment is also insured forcharges of a like material subsequently introduced, while when adifferent material is to be 'dried the vacuum-valve and thermostat arereset to correspond to the new conditions desired.

What I claim is;- y

In a drying apparatus, the combination of a drying-shell with a pump forexhausting the air and vapors therefrom, a valve-casing mounted upon theshell and having a valveseat and a suction-chamber above said seat, apipe h3 for securing the valve-casing to the exterior of the shell andestablishing communication between the interior of the shell and thesuction-chamber, an air-inlet valve openL ing within the suction-chamber and provided with a valve-stem, apivoted beam engaged bythe valve-stem, a sliding weight on one of the beam-arms, and a secondweight on the other beam-arm, substantially as specified.

Signed by me at New York city, county and State of New York, this 12thday of Oc'- tober, 1900.

ALEXANDER P. MENDE.

